An oscilloscope is an electronic device used to display and/or analyze the waveform of electronic signals. In its simplest form, an oscilloscope draws a graph of instantaneous signal voltage as a function of time. Typically, the graph displays time from left to right on the horizontal scale, and instantaneous voltage appears typically appears on a vertical scale with positive values going upward, and optionally with negative values going downward from a zero point.
Several types and forms of oscilloscopes have been developed over the years. An early form of oscilloscope, known as a cathode-ray oscilloscope, created a focused electron beam that would move in patterns across the face of a cathode ray tube (CRT) to produce a graph. Today's oscilloscopes typically use a computer processor to generate the graph and display the graph on a liquid crystal or other type of display.
Prior oscilloscopes have traditionally been large in size, often requiring a size similar to that of a suitcase, and a weight that is too great for easy lifting and movement. Such oscilloscopes are not desirable for use in small spaces or in operations where frequent movement of the oscilloscope is required. For example, an oscilloscope may be desired for use as a vehicle engine analyzer, such that secondary ignition waveforms or other patterns can be displayed in graphic form. However, most vehicle service garages have limited space, and many garages have multiple bays. Thus, an oscilloscope that is takes up a large space and/or is cumbersome to move is not desirable.
In addition, prior oscilloscopes have been traditionally stand-alone units. In areas with limited space such as service garages, it is desirable to have a portable and small device that can serve multiple functions. While the prior art has taught that an oscilloscope may be provided with other functionality, such as that of a digital multimeter (DMM) as described in U.S. Pat. No. 4,034,291, to Allen et al., to date general electronic devices have not been provided with add-on oscilloscope functionality.
Accordingly, it is desirable to provide an improved adapter device that enables a portable electronic device to function as an oscilloscope.